The present invention relates to a device for three-dimensional investigation of an object.
A device of this kind is known from DE 40 35 799. In that patent, an illuminating grid with a pixel size is imaged on a receiver array, which matches the pixel size of the photosensitive areas of the receiver array or is a whole-number multiple of said array. The diaphragm action of the receiver array is utilized. A system of this kind has the disadvantage that during the evaluation of images taken from various object planes to determine the depth values, the absolute brightness values are always evaluated and their maximum must be determined.
A device that makes it possible to determine the distance of a measured location with zero signal detection and with anamorphic imaging of a point is also known. The light from a laser diode is imaged on the object to be illuminated and the light reflected from the object is imaged by an anamorphic lens in such fashion that an approximately circular image of the point results in an intermediate plane between the two focal planes defined by the anamorphic lens. Outside this intermediate plane, with sufficient evaluation of the image by radiation receivers designed for the purpose, a system of this kind supplies a directional signal that indicates in which direction the position of the measured object differs from the set position. Systems of this kind are used in compact disk players. However, only a single point on the object is picked up in the course of this process. Therefore, measurements using a system of this kind require a great deal of time in metrology, with many measurement points having to be detected in a short time. This is especially true when large areas of the object are to be measured.